build: do not add generic release docker tag
build: do not add generic release docker tag

To support upgrades, the operator relies on a changing tag
between versions so that when a pod spec is updated, k8s will
restart the pod due to the new image name. If the image name
does not change, the operator cannot control the upgrade deployment.
Therefore, we do not support a generic docker tag such as
rook/ceph:release and we expect specific version tags to be
specified in the operator such as rook/ceph:v1.0.0.
The master build is tagged with a generic tag for convenience
of testing the latest builds, but it is important to note that
upgrades are not supported between master builds.

Signed-off-by: travisn <a8b474fdb3f77f44446f0ab9ddca8147b09b3a9e@redhat.com>

rook/rook,rook/nfs,rook/rook,rook/nfs,rook/rook,rook/nfs,rook/rook,rook/rook